The present disclosure relates in general to turbine systems, and more particularly high-speed propulsion system and inlet cooling for such high-speed propulsion systems.
High-speed propulsion turbine systems are designed to facilitate supersonic and hypersonic air transport. For example, a conventional gas turbine system includes a compressor section, a combustor section, and at least one turbine section. The compressor section is configured to compress air as the air flows through the compressor section. The air is then flowed from the compressor section to the combustor section, where it is mixed with fuel and combusted, generating a hot gas flow. The hot gas flow is provided to the turbine section, which utilizes the hot gas flow by extracting energy from it to power the compressor, and create thrust by expelling these from the engine at high speeds.
One of the challenges of developing high-speed propulsion turbine system is managing the extreme stagnation conditions at the inlet during high speed flight. Traditional methods of approaching the problem include cocooning of the gas turbine engine and allowing the high temperature flow to bypass the turbomachinery and directly enter the combustion system. While cocooning at design speeds keeps the high temperature air out of the turbomachinery, the turbomachinery has to be designed to accommodate significantly higher air temperatures to allow the aircraft to accelerate to design speeds. This requires new, expensive high temperature alloys to be developed and a redesign of the turbomachinery to accommodate high temperatures.
Development costs for any high speed propulsion system are high and first time yield is low as most applications are built from a new centerline and limited opportunities exist for ground testing at representative conditions.
Accordingly a high speed propulsion turbine system that minimizes development and unit costs by leveraging existing engine technology, while providing a novel solution for inlet cooling and high-speed flight is desirable.